Curve in Drafting becoming Straight Lines

Hello, I'm fairly confident you experienced a bug that I fixed in the v2.4.2 release where the large radius arc on the top of this part became tessellated into flat facet segments during extrusion instead of staying a nice cylindrical surface. Can you confirm that is what is happening on your end and check Settings->About and see if you're updated to v2.4.2. If you're on v2.4.2, please attached some screenshots here because I'm not seeing anything wrong on my end with the attached JC3 file. Thanks!

Thanks for your patience on this one. I spoke with Scott, got the missing context on how you're moving the part across, and I've now reproduced it here — so scratch my earlier guess about the extrusion fix in v2.4.2, that was a different bug.

Here's what's going on. Your top edge is a single R8092 mm arc sweeping just under 11°. That arc is being imported into Plasma perfectly intact — I verified the actual part data on my end and the arc is there, with the correct radius and sweep. Nothing is lost on the way in, and it doesn't matter whether you use Send To, Import From Drafting, or go out through a DXF and back — all three land the same, correct geometry.

What's wrong is purely how Plasma draws it on screen. When Plasma renders an arc it chops it into straight facets, and it decides how many facets to use from the angle of the arc alone, ignoring the radius. On a normal hole that's invisible. On a 8-metre radius it gives you exactly two facets across the whole edge — about 9 mm off the true curve at the middle. That's the kink you're seeing.

The good news is that this is a display problem only. The cut file is generated from the real arc, not from what's drawn — so the arc is preserved all the way through and posts out as a proper arc move. If you've already cut this part it should have come off the table as a smooth curve. If it didn't, tell me and I'll dig further, because that would be something separate.

The fix is to size those facets from the radius instead of the angle, the same way Drafting already does it. I've got a plan written up and it's going onto the schedule now. I'll follow up here when it ships.

The bug has been fixed and will be in the next release in a couple days.